X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Fmem.c;h=f833f97564e82d742d6884d8255e056d4a79dfd0;hb=a2f44b27303a5353859d77a3e96a1d3f33f56ab7;hp=29c41f4418c065d9aa8a447ae34f984e2cf3f321;hpb=134734d875a0a48d994ef20b9905209b4b8b6f75;p=linux-2.6.git diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 29c41f441..f833f9756 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -8,7 +8,6 @@ * Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar */ -#include #include #include #include @@ -20,13 +19,14 @@ #include #include #include -#include #include #include #include #include #include #include +#include +#include #include #include @@ -35,6 +35,22 @@ # include #endif +static inline int range_is_allowed(unsigned long from, unsigned long to) +{ + unsigned long cursor; + + cursor = from >> PAGE_SHIFT; + while ((cursor << PAGE_SHIFT) < to) { + if (!devmem_is_allowed(cursor)) { + printk ("Program %s tried to read /dev/mem between %lx->%lx.\n", + current->comm, from, to); + return 0; + } + cursor++; + } + return 1; +} + /* * Architectures vary in how they handle caching for addresses * outside of main memory. @@ -88,26 +104,21 @@ static inline int uncached_access(struct file *file, unsigned long addr) } #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE -static inline int valid_phys_addr_range(unsigned long addr, size_t *count) +static inline int valid_phys_addr_range(unsigned long addr, size_t count) { - unsigned long end_mem; - - end_mem = __pa(high_memory); - if (addr >= end_mem) + if (addr + count > __pa(high_memory)) return 0; - if (*count > end_mem - addr) - *count = end_mem - addr; - return 1; } -static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t *size) +static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) { return 1; } #endif +#ifndef ARCH_HAS_DEV_MEM /* * This funcion reads the *physical* memory. The f_pos points directly to the * memory location. @@ -119,7 +130,7 @@ static ssize_t read_mem(struct file * file, char __user * buf, ssize_t read, sz; char *ptr; - if (!valid_phys_addr_range(p, &count)) + if (!valid_phys_addr_range(p, count)) return -EFAULT; read = 0; #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED @@ -157,6 +168,8 @@ static ssize_t read_mem(struct file * file, char __user * buf, */ ptr = xlate_dev_mem_ptr(p); + if (!range_is_allowed(p, p+count)) + return -EPERM; if (copy_to_user(buf, ptr, sz)) return -EFAULT; buf += sz; @@ -177,7 +190,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf, unsigned long copied; void *ptr; - if (!valid_phys_addr_range(p, &count)) + if (!valid_phys_addr_range(p, count)) return -EFAULT; written = 0; @@ -214,13 +227,13 @@ static ssize_t write_mem(struct file * file, const char __user * buf, */ ptr = xlate_dev_mem_ptr(p); + if (!range_is_allowed(ptr, ptr+sz)) + return -EPERM; copied = copy_from_user(ptr, buf, sz); if (copied) { - ssize_t ret; - - ret = written + (sz - copied); - if (ret) - return ret; + written += sz - copied; + if (written) + break; return -EFAULT; } buf += sz; @@ -232,6 +245,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf, *ppos += written; return written; } +#endif #ifndef __HAVE_PHYS_MEM_ACCESS_PROT static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, @@ -247,13 +261,42 @@ static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, } #endif +#ifndef CONFIG_MMU +static unsigned long get_unmapped_area_mem(struct file *file, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags) +{ + if (!valid_mmap_phys_addr_range(pgoff, len)) + return (unsigned long) -EINVAL; + return pgoff << PAGE_SHIFT; +} + +/* can't do an in-place private mapping if there's no MMU */ +static inline int private_mapping_ok(struct vm_area_struct *vma) +{ + return vma->vm_flags & VM_MAYSHARE; +} +#else +#define get_unmapped_area_mem NULL + +static inline int private_mapping_ok(struct vm_area_struct *vma) +{ + return 1; +} +#endif + static int mmap_mem(struct file * file, struct vm_area_struct * vma) { size_t size = vma->vm_end - vma->vm_start; - if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, &size)) + if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) return -EINVAL; + if (!private_mapping_ok(vma)) + return -ENOSYS; + vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, size, vma->vm_page_prot); @@ -336,6 +379,8 @@ static ssize_t read_kmem(struct file *file, char __user *buf, ssize_t low_count, read, sz; char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ + return -EPERM; + read = 0; if (p < (unsigned long) high_memory) { low_count = count; @@ -411,130 +456,7 @@ static ssize_t read_kmem(struct file *file, char __user *buf, return read; } - -static inline ssize_t -do_write_kmem(void *p, unsigned long realp, const char __user * buf, - size_t count, loff_t *ppos) -{ - ssize_t written, sz; - unsigned long copied; - - written = 0; -#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED - /* we don't have page 0 mapped on sparc and m68k.. */ - if (realp < PAGE_SIZE) { - unsigned long sz = PAGE_SIZE - realp; - if (sz > count) - sz = count; - /* Hmm. Do something? */ - buf += sz; - p += sz; - realp += sz; - count -= sz; - written += sz; - } -#endif - - while (count > 0) { - char *ptr; - /* - * Handle first page in case it's not aligned - */ - if (-realp & (PAGE_SIZE - 1)) - sz = -realp & (PAGE_SIZE - 1); - else - sz = PAGE_SIZE; - - sz = min_t(unsigned long, sz, count); - - /* - * On ia64 if a page has been mapped somewhere as - * uncached, then it must also be accessed uncached - * by the kernel or data corruption may occur - */ - ptr = xlate_dev_kmem_ptr(p); - - copied = copy_from_user(ptr, buf, sz); - if (copied) { - ssize_t ret; - - ret = written + (sz - copied); - if (ret) - return ret; - return -EFAULT; - } - buf += sz; - p += sz; - realp += sz; - count -= sz; - written += sz; - } - - *ppos += written; - return written; -} - - -/* - * This function writes to the *virtual* memory as seen by the kernel. - */ -static ssize_t write_kmem(struct file * file, const char __user * buf, - size_t count, loff_t *ppos) -{ - unsigned long p = *ppos; - ssize_t wrote = 0; - ssize_t virtr = 0; - ssize_t written; - char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ - - if (p < (unsigned long) high_memory) { - - wrote = count; - if (count > (unsigned long) high_memory - p) - wrote = (unsigned long) high_memory - p; - - written = do_write_kmem((void*)p, p, buf, wrote, ppos); - if (written != wrote) - return written; - wrote = written; - p += wrote; - buf += wrote; - count -= wrote; - } - - if (count > 0) { - kbuf = (char *)__get_free_page(GFP_KERNEL); - if (!kbuf) - return wrote ? wrote : -ENOMEM; - while (count > 0) { - int len = count; - - if (len > PAGE_SIZE) - len = PAGE_SIZE; - if (len) { - written = copy_from_user(kbuf, buf, len); - if (written) { - ssize_t ret; - - free_page((unsigned long)kbuf); - ret = wrote + virtr + (len - written); - return ret ? ret : -EFAULT; - } - } - len = vwrite(kbuf, (char *)p, len); - count -= len; - buf += len; - virtr += len; - p += len; - } - free_page((unsigned long)kbuf); - } - - *ppos = p; - return virtr + wrote; -} - -#if defined(CONFIG_ISA) || !defined(__mc68000__) +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) static ssize_t read_port(struct file * file, char __user * buf, size_t count, loff_t *ppos) { @@ -563,8 +485,11 @@ static ssize_t write_port(struct file * file, const char __user * buf, return -EFAULT; while (count-- > 0 && i < 65536) { char c; - if (__get_user(c, tmp)) + if (__get_user(c, tmp)) { + if (tmp > buf) + break; return -EFAULT; + } outb(c,i); i++; tmp++; @@ -586,6 +511,18 @@ static ssize_t write_null(struct file * file, const char __user * buf, return count; } +static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, + struct splice_desc *sd) +{ + return sd->len; +} + +static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out, + loff_t *ppos, size_t len, unsigned int flags) +{ + return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); +} + #ifdef CONFIG_MMU /* * For fun, we are using the MMU for this. @@ -613,7 +550,8 @@ static inline size_t read_zero_pagealigned(char __user * buf, size_t size) count = size; zap_page_range(vma, addr, count, NULL); - zeromap_page_range(vma, addr, count, PAGE_COPY); + if (zeromap_page_range(vma, addr, count, PAGE_COPY)) + break; size -= count; buf += count; @@ -680,11 +618,14 @@ out: static int mmap_zero(struct file * file, struct vm_area_struct * vma) { + int err; + if (vma->vm_flags & VM_SHARED) return shmem_zero_setup(vma); - if (zeromap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot)) - return -EAGAIN; - return 0; + err = zeromap_page_range(vma, vma->vm_start, + vma->vm_end - vma->vm_start, vma->vm_page_prot); + BUG_ON(err == -EEXIST); + return err; } #else /* CONFIG_MMU */ static ssize_t read_zero(struct file * file, char * buf, @@ -741,7 +682,7 @@ static loff_t memory_lseek(struct file * file, loff_t offset, int orig) { loff_t ret; - mutex_lock(&file->f_dentry->d_inode->i_mutex); + mutex_lock(&file->f_path.dentry->d_inode->i_mutex); switch (orig) { case 0: file->f_pos = offset; @@ -756,7 +697,7 @@ static loff_t memory_lseek(struct file * file, loff_t offset, int orig) default: ret = -EINVAL; } - mutex_unlock(&file->f_dentry->d_inode->i_mutex); + mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); return ret; } @@ -773,30 +714,36 @@ static int open_port(struct inode * inode, struct file * filp) #define open_kmem open_mem #define open_oldmem open_mem -static struct file_operations mem_fops = { +#ifndef ARCH_HAS_DEV_MEM +static const struct file_operations mem_fops = { .llseek = memory_lseek, .read = read_mem, .write = write_mem, .mmap = mmap_mem, .open = open_mem, + .get_unmapped_area = get_unmapped_area_mem, }; +#else +extern struct file_operations mem_fops; +#endif -static struct file_operations kmem_fops = { +static const struct file_operations kmem_fops = { .llseek = memory_lseek, .read = read_kmem, - .write = write_kmem, .mmap = mmap_kmem, .open = open_kmem, + .get_unmapped_area = get_unmapped_area_mem, }; -static struct file_operations null_fops = { +static const struct file_operations null_fops = { .llseek = null_lseek, .read = read_null, .write = write_null, + .splice_write = splice_write_null, }; -#if defined(CONFIG_ISA) || !defined(__mc68000__) -static struct file_operations port_fops = { +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) +static const struct file_operations port_fops = { .llseek = memory_lseek, .read = read_port, .write = write_port, @@ -804,25 +751,29 @@ static struct file_operations port_fops = { }; #endif -static struct file_operations zero_fops = { +static const struct file_operations zero_fops = { .llseek = zero_lseek, .read = read_zero, .write = write_zero, .mmap = mmap_zero, }; +/* + * capabilities for /dev/zero + * - permits private mappings, "copies" are taken of the source of zeros + */ static struct backing_dev_info zero_bdi = { .capabilities = BDI_CAP_MAP_COPY, }; -static struct file_operations full_fops = { +static const struct file_operations full_fops = { .llseek = full_lseek, .read = read_full, .write = write_full, }; #ifdef CONFIG_CRASH_DUMP -static struct file_operations oldmem_fops = { +static const struct file_operations oldmem_fops = { .read = read_oldmem, .open = open_oldmem, }; @@ -849,7 +800,7 @@ static ssize_t kmsg_write(struct file * file, const char __user * buf, return ret; } -static struct file_operations kmsg_fops = { +static const struct file_operations kmsg_fops = { .write = kmsg_write, }; @@ -858,14 +809,18 @@ static int memory_open(struct inode * inode, struct file * filp) switch (iminor(inode)) { case 1: filp->f_op = &mem_fops; + filp->f_mapping->backing_dev_info = + &directly_mappable_cdev_bdi; break; case 2: filp->f_op = &kmem_fops; + filp->f_mapping->backing_dev_info = + &directly_mappable_cdev_bdi; break; case 3: filp->f_op = &null_fops; break; -#if defined(CONFIG_ISA) || !defined(__mc68000__) +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) case 4: filp->f_op = &port_fops; break; @@ -899,7 +854,7 @@ static int memory_open(struct inode * inode, struct file * filp) return 0; } -static struct file_operations memory_fops = { +static const struct file_operations memory_fops = { .open = memory_open, /* just a selector for the real open */ }; @@ -907,12 +862,11 @@ static const struct { unsigned int minor; char *name; umode_t mode; - struct file_operations *fops; + const struct file_operations *fops; } devlist[] = { /* list of minor devices */ {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops}, - {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops}, {3, "null", S_IRUGO | S_IWUGO, &null_fops}, -#if defined(CONFIG_ISA) || !defined(__mc68000__) +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops}, #endif {5, "zero", S_IRUGO | S_IWUGO, &zero_fops}, @@ -935,14 +889,11 @@ static int __init chr_dev_init(void) printk("unable to get major %d for memory devs\n", MEM_MAJOR); mem_class = class_create(THIS_MODULE, "mem"); - for (i = 0; i < ARRAY_SIZE(devlist); i++) { - class_device_create(mem_class, NULL, - MKDEV(MEM_MAJOR, devlist[i].minor), - NULL, devlist[i].name); - devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor), - S_IFCHR | devlist[i].mode, devlist[i].name); - } - + for (i = 0; i < ARRAY_SIZE(devlist); i++) + device_create(mem_class, NULL, + MKDEV(MEM_MAJOR, devlist[i].minor), + devlist[i].name); + return 0; }